Background and Aim: The emergence of antimicrobial resistance (AMR) in commensal organism, such as Escherichia coli of food animals, is an alarming issue for global health. It increases the possibility of transmitting AMR determinant(s) to human bacterial pathogens by transferable genetic materials, particularly by plasmids. Hence, it is important to know which resistant genes are being carried by commensal organisms in food chain in a country and their level of temporal loads. As a result, pre-emptive measures can be advocated with an aim to reduce their risks in their primary source of circulation which consequently would benefit the public health. Materials and Methods: Commensal E. coli strains from broiler chickens on randomly selected 30 farms and the farm environments were examined for the frequencies of isolation of resistant strains to oxytetracycline and ciprofloxacin. Five birds were randomly selected from each farm to collect cloacal swab samples (total of 150 samples). Furthermore, a total of 150 environmental samples comprising one each from feed, water, soil, litter, and litter damping site of each farm were screened for the isolation of commensal E. coli strains. Strains thus obtained were initially tested for their resistance to oxytetracycline and ciprofloxacin by Kirby–Bauer disk diffusion method. Oxytetracycline-resistant strains were further screened for the presence of resistance determining genes, namely, tetA, tetB, and tetC by uniplex polymerase chain reactions. Risks associated with the isolation frequency of oxytetracycline- and ciprofloxacin-resistant E. coli were also assessed by univariable logistic regression analysis. Results: The results revealed that all E. coli isolates, regardless of the source of origin, were resistant to oxytetracycline, while 78.4% (95% confidence interval [CI] 69.1-85.5%) showed resistance to ciprofloxacin. All the randomly selected (20) oxytetracycline-resistant strains harbored the tetA gene, whereas tetB and tetC were reported in three and two isolates, respectively. After univariable analysis, only one variable, that is, strain 1 of broiler chickens compared to two other strains was found to be positively associated with the isolation of ciprofloxacin-resistant E. coli (odds ratio 12.75 [95% CI 1.0- 157.1], p=0.047). Conclusion: Resistance emerged against oxytetracycline and ciprofloxacin in commensal E. coli strains circulating in live poultry and farm environments in Bangladesh seems to be very high. Thus, human infection with drug-resistant E. coli strains through food chain will critically compromise the therapeutic measures currently available.

Irrawaddy squirrel ( Callosciurus pygerythrus ) may play an important role in the transmission of zoonotic bacteria, but little is known about the carriage of zoonotic bacteria in this common frugivorous rodent in Bangladesh. We aimed to investigate the presence of common zoonotic bacterial pathogens in Irrawaddy squirrel in the southeast part of Bangladesh. A total of 27 rectal and 27 oro‐nasal swabs were collected from 27 healthy wild Irrawaddy squirrels. Four common zoonotic bacteria were isolated following routine laboratory procedures, and were identified based on colony morphology, and biochemical and staining properties. The pathogenic potential of the identified bacteria was confirmed by detection of virulence genes by PCR . All isolates were subjected to antimicrobial susceptibility test against seven antibiotics from six generic groups which are commonly used in human and veterinary medicine in Bangladesh. The prevalence of Escherichia coli , Salmonella spp., Yersinia spp. and Staphylococcus spp. was 44.4% (95% CI , 32.0–57.6), 13% (95% CI , 6.1–24.7), 44.4% (95% CI , 32.0–57.6), and 72.2% (95% CI , 59.0–82.5), respectively. We identified potential zoonotic virulence genes in all of these four bacterial species. Antimicrobial susceptibility testing revealed the presence of several multidrug resistant bacterial strains in squirrels. To the best of our knowledge, this is the first report in Bangladesh of the detection of antibiotic resistant zoonotic bacteria in Irrawaddy squirrels. The findings underpin the role of Irrawaddy squirrel as a source of pathogenic antibiotic resistant bacteria, consequently, fruit rejected because of squirrel consumption and squirrel‐bites deserve more concern than previously.

Background and Aim:Newcastle disease is one of the most common diseases affecting poultry in Bangladesh. The disease can cause up to 100% mortality but is preventable if birds are timely and properly vaccinated with a vaccine of standard virus titer. Different live vaccines are commercially available in the country - most, if not all, are produced using lentogenic strains of the virus with variable virulence. One of the disadvantages of these vaccines is that they are not stable at high environmental temperature, and therefore, a proper cold chain must be maintained during transportation and storage. Information on how long these vaccine viruses can withstand environmental temperature, which is near the vicinity of 37°C in the summer season in Bangladesh, is scanty. The aim of this research was to measure the effect of temperature on virus titer of live ND virus vaccines and to develop a real-time reverse transcription polymerase chain reaction (rRT-PCR) standard curve to indirectly determine hemagglutination (HA) titer of virus by this highly sensitive method.Materials and Methods:In this study, thermostability of five commercial live vaccines containing LaSota, F, Clone 30, and B1 type LaSota strains was observed for up to 35 days keeping them at 37°C. From the most thermostability yielding sample, two rRT-PCR standard curves were developed: (1) By plotting the cycle threshold (CT) values as obtained from 10-fold serial dilutions up to 10−3 against their corresponding log (to the base 10) dilutions and (2) by plotting the CT values obtained from serial HA dilutions up to 2−4 against their corresponding HA titer dilutions. The PCR efficiencies based on which the graphs were fitted were also evaluated.Results:The vaccine from the LaSota strain withstood 37°C for 35 days with a gradual declination of HA titer over time, and this vaccine also had the highest initial HA titer, which was 211. The vaccine made from F strain was inactivated quickly, and it had the lowest HA titer at the beginning of the study. The first standard curve developed can be used to assess the level of virus titer in a diluted sample compared with the titer in the original undiluted vaccine preparation by plotting the CT value obtained from the dilution by rRT-PCR. The second standard curve can be used to calculate the HA titer of a vaccine dilution by plotting the CT value as obtained from the dilution by rRT-PCR.Conclusion:The regression equations for the first and second graphs were y=−3.535x+14.365 and y=−1.081x+13.703, respectively, suggesting that, for every 3.53 cycles, the PCR product would have increased 10 times and 2 times for every 1.08 cycles, respectively, indicating nearly (but not exactly) 100% PCR efficiency.

No abstract

one group shed valuable light on the other. The relatively low incidence of many arenavirus infections-especially in the New World where some are recognized only in outbreak form-as well as historically undeveloped research infrastructure and civil unrest in many areas where arenavirus are endemic has impeded clinical study. The natural history of disease and underlying pathophysiology remain poorly understood. Nevertheless, there is reasonable evidence of efficacy of the guanosine analogue ribavirin and convalescent immune plasma for these viruses, although further study employing more modern techniques and standards is certainly warranted. In addition, there are concerns regarding availability, toxicity, and ease of administration of ribavirin and immune plasma. New approaches are needed. The end of some of the civil conflicts in endemic areas for Lassa fever in West Africa, followed by the large 2013-16 outbreak of Ebola virus disease in the region that served to refocus attention on viral hemorrhagic fevers, especially Lassa, has renewed interest and, to a degree, resources, for more in-depth study of Arenaviruses, including efficacy of new drugs. Interest is particularly high in the RNA polymerase inhibitor favipiravir, for which promising pre-clinical data are available. Establishing newer more efficacious and safer treatments of Arenavirus infection will require continued investment in both preclinical and clinical study, including development of the required infrastructure for clinical trials in West Africa. It will be important to conduct more systematic clinical observation of patients with arenavirus infection to better understand the pathogenesis of disease and identify logical points of intervention. Lastly, while difficult to quantify, it is likely that much could be gained in terms of reducing mortality simply by enhancing infrastructure required to deliver modern quality supportive care in the endemic areas for arenaviruses, which include many of the world's poorest regions.